- Libro electrónicoSchaum's Outline of Trigonometry, Sixth EditionRobert E. Moyer
- Libro electrónicoSchaum's Outline of College Algebra, Fifth EditionMurray R. Spiegel
- Libro electrónicoSchaum's Outline of College Algebra, Fourth EditionMurray R. Spiegel
- Libro electrónicoSchaum's Outline of Trigonometry, 5th EditionRobert E. Moyer